Case ReportEpidermoid Cysts in a Wandering Spleen: An Unusual Enigma

Sarah E. Algino,1 Siena Sorrentino,2 David T. Luyimbazi,3 and Douglas J. Grider 4

1Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, USA2Virginia Tech, Blacksburg, Virginia, USA3Department of Surgery, Carilion Clinic and Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA4Department of Basic Science Education, Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA

Correspondence should be addressed to Douglas J. Grider; djgrider@carilionclinic.org

Received 7 July 2019; Accepted 6 November 2019; Published 20 November 2019

Academic Editor: Marcus L. Quek

Copyright © 2019 Sarah E. Algino et al. This is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Epidermoid splenic cysts are rare lesions in the spleen. These cysts are characterized by a stratified squamous epithelial lining,internal septations, and calcification. Congenital in origin, epidermoid splenic cysts are postulated to arise from misfolding andmesothelial cell incorporation into the splenic parenchyma. This report presents a unique case of an 18-year-old woman with anepidermoid splenic cyst in a congenital wandering spleen. Computed tomography and transabdominal ultrasound imagingalong with immunochemistry staining confirmed the diagnosis. To the authors’ knowledge, this is the first reported case of anepidermoid cyst in a wandering spleen.

1. Introduction

Splenic epidermoid cysts are rare, only accounting foraround 10% of splenic cysts, and can be described as pri-mary, nonparasitic cysts that are typically congenital inorigin [1–3]. Epidermoid splenic cysts are characterizedby having an epithelial cell lining composed of stratifiedsquamous epithelium, variable cuboidal mesothelial cells,and rarely mucous cells. This epithelial lining distinguishesprimary from secondary cysts or pseudocysts which lackan epithelial lining [3].

Epidermoid splenic cysts most commonly affect individ-uals of a young age and have varied clinical presentations.Most cases are asymptomatic; however, cysts larger in sizemay present with abdominal symptoms, such as discomfort,fullness, nausea, vomiting, pain, or a tender palpable mass[1–4]. Abdominal ultrasonography (US) or computerizedtomography (CT) are the primary imaging modalitiesemployed for diagnosing splenic epidermoid cysts. How-ever, histological examination is required to make thediagnosis. Thus, partial or total splenectomy is the optimaltreatment [3, 4].

An epidermoid splenic cyst is an unencapsulated, usuallycircumscribed cystic mass located in the spleen. Due to the

size of the cyst and its location in splenic parenchyma,splenomegaly is commonly seen on US and CT studies.Grossly, epidermoid splenic cysts are greyish white inappearance. Histologically, a stratified squamous epitheliallining is present lining the cyst wall interior. Internal sep-tations and calcification are variably present. Positivestaining for CK5/6 and CEA by immunohistochemistryhelps make the diagnosis. If there is a mesothelial flat tocuboidal cell lining component, it will also be CK5/6 pos-itive, along with calretinin or other mesothelial markers byimmunohistochemistry [3–5].

Reported is a unique case of an epidermoid splenic cystdiscovered in an 18-year-old woman with travel history toAustralia and Sardinia, regions endemic to cystic echinococ-cosis, also commonly known as Hydatid disease.

2. Case Report

An 18-year-old woman with recent travel history to Australiaand Sardinia presented with constant lower abdominal full-ness for one-year duration, with increased intensity overthe last 3-4 months. The patient denied any occurrence ofnausea, vomiting, or pain. Transvaginal ultrasound revealeda large cystic mass spanning the abdominal and pelvic

regions. The only notable laboratory finding was a mildelevation in tumor marker CA 19-9. Subsequent CT imag-ing exhibited an enlarged, wandering spleen measuring24:5 × 16:0 × 12:0 cm, in the patient’s left lower abdomenand extending into the anterior mid pelvis (Figure 1).No evidence of venous or arterial obstruction was noted.A 16:0 × 15:7 × 1:4 cm mass in the inferior aspect of thespleen was seen composed of a large central cystic spacewith several peripheral cystic structures of varying sizes.Minimal calcification was demonstrated along the septa-tions within the lesion. In addition, an 1:7 × 1:5 × 1:6 cmsolid-appearing region was detected at the left mid anterioraspect of the spleen, possibly representing a portion of thevascular pedicle. The patient presented no other notablemedical history or physical findings. An open splenectomywas deemed appropriate for treatment in order to preventtorsion of the splenic pedicle.

Extirpation of the spleen revealed a circumscribed16 cm gray-white, smooth, and fibrotic mass. Serial sec-tioning of the mass showed a large cyst filled with yellowfluid. The lining was smooth, tan and focally hemorrhagic.Many smaller peripheral cystic lesions of variable sizesemanated from this larger cystic space, measuring between0.4 and 0.3 cm. No echinococcal cysts or papillary excres-cences were detected. Microcalcifications were noted inmany sites of the cyst wall septations. Histology showeda variable stratified squamous cell epithelium and simplecuboidal to flat mesothelial cell lining on densely fibroticwalls of variably sized cystic spaces. (Figure 2) Immuno-histochemistry was positive for CK5/6 and CEA in thesquamous lining of the cystic spaces, confirming a splenicepidermoid cyst. (Figures 3(a)–3(c)) The mesothelial cellswere also CK5/6 but were also calretinin positive. Muci-carmine focally marked mucous cells within the squamousepithelial lining. (Figure 4) No skin adnexa or other meso-dermal or endodermal structures were seen, helping toexclude a dermoid cyst or cystic teratoma. EchinococcusIgG study was negative, helping to exclude a hydatid cyst.Rare areas of stratified squamous epithelium had focalmucous-type cells, positive on mucicarmine-stained tissuesections, a feature also described in epidermoid cysts [6].

The pedicle of the wandering spleen had lymphatic, arte-rial and venous vessels of variable sizes and somewhat dis-ordered distribution, mimicking a vascular malformation.

3. Discussion

When examined, epidermoid splenic cysts appear smoothand grey-white in color grossly. Histologically, they have aminimum of stratified squamous epithelial cyst lining butcan also have cuboidal to flat mesothelial cells and rarelymucous cells. Septations or trabeculations within the cystmay also be present. The cysts contain fluid that varies fromserous to purulent. Epidermoid splenic cysts are congenitaland are postulated to arise during the development of thespleen in utero, specifically from the incorporation of meso-thelial cells into the splenic parenchyma [1, 2, 6].

The differential diagnosis includes a variety of benignsplenic abnormalities including hydatid cysts, lymphangio-mas, and pseudocysts. Hydatid cysts chiefly inhabit the liverand lungs; less commonly, they may also occur in the spleen[7]. Splenic hydatid cysts mirror some of the clinical featuresof epidermoid splenic cysts, namely, splenomegaly and thepresence of a large, circumscribed cystic lesion on abdominalUS. However, hydatid cysts present with different clinicalhistory and display cyst wall calcification and hyperdenseinternal membranes. These cysts are caused by the tapewormEchinococcosis granulosis and are endemic in areas wheresheep are raised, such as Asia, Central and South America,Europe, and Africa [7–9]. In addition, clinical presentationof hydatid splenic cysts involve gastrointestinal disturbancessuch as dyspepsia, gastritis, and constipation. Furthermore,hydatid splenic cysts are hyperechoic on abdominal ultra-sound while epidermoid splenic cysts are anechoic [1, 7–9].Lastly, no stratified squamous epithelial lining is present tosuggest epidermoid splenic cysts.

Splenic cystic lymphangiomas, too, present with similarclinical features of splenic epidermoid cysts, most notablysplenomegaly, abdominal fullness, and cystic massesappearing on ultrasound imaging. Patients with cystic lym-phangiomas are predominately asymptomatic. However,lymphangiomas are unique in that they are filled with eosin-ophilic, proteinaceous lymphatic fluid [10]. Splenic epider-moid cysts do not contain lymph material, rather they

Figure 1: Coronal plane CT image of large intra-abdominalwandering spleen with cystic masses.

Figure 2: Stratified squamous epithelial lined splenic cyst(epidermoid cyst) (H&E 100 magnification; 10x).

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contain serous fluid of varied color. Additionally, histologicalexamination reveals flattened endothelial lining in cysticlymphangiomas, while epidermoid cysts display stratifiedsquamous epithelial lining. Another remarkable factor differ-entiating splenic cystic lymphangiomas from splenic epider-moid cysts is that lymphangiomas present with dilation ofthe lymphatic vessels of the splenic parenchyma while novenous abnormalities are typically associated with splenicepidermoid cysts [11, 12].

Splenic pseudocysts, much like the other diagnosticconsiderations, display commonalities with epidermoidsplenic cysts, including similar presentation on imaging;thus, histology is vital in diagnosing pseudocysts. Pseudo-cysts are sometimes categorized as secondary cysts due totheir lack of epithelial lining internally. Epidermoid cystsof the spleen are primarily due to epithelial lining. Histol-ogy further shows that pseudocyst walls are lined solely byfibrous tissue, often with associated hemosiderin-ladenmacrophages [13, 14].

Dermoid cysts of the spleen also known as cystic terato-mas should, too, be ruled out when considering cysts of thespleen. Dermoid cysts of the spleen are rare in occurrenceand have a similar clinical presentation to previouslydiscussed splenic cysts, consisting of lower abdominal pain,fullness of the abdomen, and a cystic lesion of the spleenpresent on imaging findings. Ultrasound findings demon-strate a hyperechoic mass in the spleen, distinguishing der-moid cysts from epidermoid splenic cysts which areanechoic [7–9, 15]. Dermoid cysts can be distinguished histo-logically through a simple stratified epithelial lining withsebaceous portions as well as sclerotic and hyaline changespresent in the connective tissue of the cyst [15]. This divergesfrom the characteristic appearance of splenic epidermoidcysts which demonstrate stratified squamous epithelial lining[6, 15]. However, both epidermoid and dermoid splenic cystsalike may display mucous cells along their lining [6, 16].

(a) (b)

(c)

Figure 3: (a) Splenic epidermoid cyst with stratified squamous epithelial with focal mucous cells and simple flat mesothelial cell cyst lining(H&E 100 magnification; 10x). (b) CK5/6 IHC marking both stratified squamous epithelial and simple flat mesothelial cell lining cells (100magnification; 10x). (c) CEA IHC marking stratified squamous epithelial cells (200 magnification; 20x).

Figure 4: Mucicarmine marking mucin collection in the midst ofstratified squamous epithelium in a splenic epidermoid cyst (600magnification; 60x).

3Case Reports in Surgery

Dermoid cysts can also present with varied contents such ashair shafts and pulp-like material further distinguishingthem from splenic epidermoid cysts [16, 17].

While the origin of epidermoid splenic cysts is still underinvestigation, previous case reports and research all agreethat epidermoid splenic cysts are congenital, primary, non-traumatic, benign cysts [1–4]. Epidermoid cysts are postu-lated to derive from either mesothelial lined cysts ormesothelial cell misfolding in utero, as evidence by mesothe-lial cell incorporation into areas normally occupied primarilyby squamous epithelial cells. With immunohistochemistry,epidermoid splenic cysts display stratified squamousepithelial cell lining with focal areas of metaplasia, indicatingpossible divergence from mesothelial lined cysts [6]. Thisincorporation of mesothelial cells is a prominent determin-ing factor identifying splenic epidermoid cysts and is seenin their positive immunohistochemistry staining for CEA[6]. These cysts are predominately discovered in youngfemale patients; however, neither race nor descent is a distin-guishing factor. Smaller cysts generally are asymptomaticand are discovered incidentally on imaging, while larger cystspresent with abdominal symptoms, such as fullness, pain,and a tender palpable mass [2, 4]. To efficiently treat epider-moid splenic cysts, one must perform partial or completesurgical removal of the spleen, as histology is crucial to con-firm the diagnosis.

Previously reported cases of epidermoid splenic cystshave not been associated with congenital wandering spleen.Wandering spleen is in itself a rare random occurrence,characteristically found by imaging studies as an accidentaldiscovery or as part of an evaluation for acute abdominalpain [18]. With wandering spleen, the spleen is hypermobileand displaces from its normal anatomic location, generallymoving into the pelvic region. Due to potential life-threatening torsion of the vascular pedicle, surgery is consid-ered the optimal treatment [1–5]. The rare finding of a con-genital wandering spleen coinciding with a congenitalsplenic epidermoid cyst is presented. The relationshipbetween these two seemingly disparate entities is unknownin this patient but are probably more than coincidentalreflecting an incident in utero involving misplaced mesothe-lial cells or mesothelial progenitor cells. Thus, it might beinformative to histologically evaluate extirpated incidentalcongenital wandering spleens to search for misplaced meso-thelial cells, mesothelial lined cysts, and epidermoid cysts.

Conflicts of Interest

All authors have no conflicts of interest to report.

References

[1] A. P. Singh Rana, M. Kaur, P. Singh, S. Malhotra, and K. A.Singh, “Splenic epidermoid cyst - a rare entity,” Journal ofClinical and Diagnostic Research, vol. 8, no. 2, pp. 175-176,2014.

[2] S. Grover, B. Garg, N. Sood, and S. Singh, “Splenic epidermoidcyst in a five-year-old child,” Journal of Clinical and DiagnosticResearch, vol. 10, no. 7, pp. ED07–ED09, 2016.

[3] S. Vuyyuru and B. Kharbutli, “Epidermoid cyst of the spleen, acase report,” International Journal of Surgery Case Reports,vol. 35, pp. 57–59, 2017.

[4] M. Thomas and B. Taiwo, “Splenic epidermoid cysts present-ing as an acute abdomen,” Postgraduate Medical Journal,vol. 70, no. 823, pp. 376-377, 1994.

[5] P. Cianci, N. Tartaglia, A. Altamura et al., “A recurrent epider-moid cyst of the spleen: report of a case and literature review,”World Journal of Surgical Oncology, vol. 14, article 98, 2016.

[6] K.-F. Bürrig, “Epithelial (true) splenic cysts. Pathogenesis ofthe mesothelial and so-called epidermoid cyst of the spleen,”The American Journal of Surgical Pathology, vol. 12, no. 4,pp. 275–281, 1988.

[7] R. Singal, K. Sandhu, A. Mittal, S. Gupta, and G. Jindal, “Agiant splenic hydatid cyst,” Baylor University Medical CenterProceedings, vol. 29, no. 1, pp. 55–57, 2016.

[8] Y. Sleiman, A. Bohlok, M. El-Khoury, P. Demetter,M. Zalcman, and I. El Nakadi, “Splenic epithelial cyst mistakenwith hydatid cyst: a case report,” International Journal ofSurgery Case Reports, vol. 53, pp. 21–24, 2018.

[9] P. Kumar, A. Hasan, M. Kumar, and V. Singh, “Isolated hyda-tid cyst of spleen: a rare case with rare presentation,” Interna-tional Journal of Surgery Case Reports, vol. 28, pp. 279–281,2016.

[10] B. Efared, G. Atsame-Ebang, A. Zabeirou et al., “Isolatedsplenic lymphangioma presenting as a huge mass causing ane-mia and abdominal distention in an adult patient: a casereport,” Journal of Medical Case Reports, vol. 12, article 97,2018.

[11] S. Y. Kim, H. J. Kwon, H. W. Park, S. Y. Lee, B. H. Son, andM. S. Kim, “Multiple cystic lymphangiomas of the spleen:radiologic and histopathologic findings,” Journal of MedicalUltrasonics, vol. 42, no. 3, pp. 409–412, 2015.

[12] S. Duvvada, D. Senapati, S. R. Challa, and T. Kalluri, “Cysticlymphangioma of spleen in adults,” BMJ Case Reports,vol. 2017, article bcr2016216267, 2017.

[13] A. L. Shrestha and P. Shrestha, “A rare encounter with anexpanding pseudocyst of the spleen,” Case Reports In Gastro-intestinal Medicine, vol. 2017, Article ID 9896856, 4 pages,2017.

[14] A. Sarwal, A. Sharma, R. Khullar, V. Soni, M. Baijal, andP. Chowbey, “Laparoscopic splenectomy for large splenicpseudocyst: a rare case report and review of literature,” Journalof Minimal Access Surgery, vol. 15, no. 1, pp. 77–79, 2019.

[15] N. Atsunori, S. Shinyo, Y. Taketoshi et al., “Dermoid cyst ofthe spleen: report of a case,” Surgery Today, vol. 29, no. 7,pp. 660–662, 1999.

[16] N. V. Adsay, F. Hasteh, J. D. Cheng, and D. S. Klimstra, “Squa-mous-lined cysts of the pancreas: lymphoepithelial cysts, der-moid cysts (teratomas), and accessory-splenic epidermoidcysts,” Seminars in Diagnostic Pathology, vol. 17, no. 1,pp. 56–65, 2000.

[17] M. Sushna, “Mature cystic teratoma of ovary with squamouscell carcinoma arising from it,” Clinical Case Reports, vol. 7,no. 4, pp. 668–671, 2019.

[18] M. Jiang, P. Chen, X. Ruan, Y. Xianwang, and Q. Huang,“Acute torsion of wandering spleen in a 17-year-old girl,”International Journal of Clinical and Experimental Medicine,vol. 8, no. 7, pp. 11621–11623, 2015.

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